With his long, salt-and-pepper beard, velvet kippah and peyot, Asher Joseph Cherkassky is more than a mere oddity amid the crucifix-bearing Ukrainians that make up his battalion. The AK-47-bearing Chabadnik, who enlisted in the Ukrainian army two years ago and was soon engaged in fierce combat against Russian separatists near Donetsk, was part of a frontline force that included the neo-Nazi Azov Battalion and other ultra-nationalist groups.